The present invention is related generally to a system for towing a vehicle and in particular is related to a device attachable to a vehicle for towing the vehicle without requiring rotation of selected vehicle wheel hubs coupled to the device. The system therefore enables the rotation of a wheel and attached tire of a vehicle to be isolated from a vehicle's drive train and/or an automatic transmission connected to a wheel hub of the vehicle and further enables towing of the vehicle with substantially direct response steerability by the towed vehicle. The invention accomplishes the automatic transmission isolation and direct response steerability by utilizing the vehicle's own suspension and steering systems.
Previous apparatus for towing a vehicle has involved connection of a towing vehicle by a tow bar to various portions of the frame or a bumper of the towed vehicle. Towing of vehicles with standard mechanical transmissions generally involves no special difficulty. However, the towing of vehicles with automatic transmissions over anything more than a short distance presents substantial problems since damage can result to the automatic transmission unless the vehicle drive shaft is disconnected or the vehicle is towed on wheels and attached tires not connected to the automatic transmission. Furthermore, current towing systems, such as tow dollys, are quite expensive and create safety hazards by towing the vehicle in an elevated position on only two wheels. There is also a substantial decrease in gas mileage efficiency when towing a vehicle elevated by a tow dolly since there is more wind resistance than towing the vehicle on all its wheels with attached tires. In addition, the tow dolly weighs approximately five hundred pounds, which is substantial additional weight to be carried by the towing vehicle.
There is an increasing percentage of vehicles (currently approximately 85%) equipped with automatic transmissions, particularly front wheel drive vehicles. Consequently, a large and increasing percentage of the population must use inefficient, unsafe and expensive apparatus to perform towing operations on those vehicles equipped with automatic transmissions. As mentioned above, if the vehicle has rear wheel drive with an automatic transmission, the automatic transmission must be disconnected to tow the vehicle on the rear wheels or must be towed backwards on its front wheels using a tow dolly to elevate the rear wheels during transport. If the vehicle has front wheel drive with an automatic transmission, the transmission must be disconnected to tow the vehicle on the front wheels, or the tow dolly must be used to elevate the front end of the vehicle during the towing operation. According to a United States Department of Commerce, Bureau of Census Report entitled, "Geographic Mobility," approximately thirty-seven million Americans move each year. Of this number, 7.4 million move to different counties within the same state and 6.1 million move interstate. This is estimated to translate into approvimately twenty-five million vehicles being relocated, and of that number at least five to seven million vehicles are towed. Many vehicles are however not towed due to the unsafe nature of transport, the inefficiency, the inconvenience of preparing the car for towing and the expense. In view of these disadvantages, the owner of the vehicle often selects the laborious, time consuming choice of driving the vehicle to the new location. Although the mobile American represents the highest percentage of towed vehicles, other applications include: (a) used car dealers transporting used cars to and from auto auctions; (b) car rental agencies returning a car dropped off at various locations could send one driver to retrieve two vehicles, and the steerbar would enable the towing of two or more vehicles; (c) the towing of vehicles behind motor homes; (d) auto salvage operations wishing to tow inoperable vehicles from a distant location to the salvage yard without damaging the transmission; (e) families who spend their summers in the north and their winters in the south could use the inventions to tow their cars; and (f) towing of a third vehicle behind a second towed vehicle.
Additional problems of towing newer types of vehicles include the difficulty of making a proper connection to the vehicle. Generally, standard tow bars are connected to, or near, one of the bumpers of the vehicle. However, in newer vehicles, for the sake of appearance and/or smoother aerodynamic shape, the bumpers are being designed flush with the sheet metal in the area of the bumpers, making connection of a tow bar more difficult. Furthermore, in order to reduce the vehicle weight to meet government gas mileage mandates, the metal thickness is being reduced in constructing the bumper and associated vehicle parts which causes the general strength of the connection to be reduced.